| |
Records |
Warning: mysql_fetch_field() expects parameter 2 to be long, string given in /home/arimmora/public_html/refbase/includes/include.inc.php on line 309
Links |
|
Author |
Solov'yov, I.A.; Domratcheva, T.; Schulten, K. |
|
| |
Title |
Separation of photo-induced radical pair in cryptochrome to a functionally critical distance |
Type |
Journal Article |
| |
Year |
2014 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep |
|
| |
Volume |
4 |
Issue |
|
Pages |
3845 |
|
| |
Keywords |
|
|
| |
Abstract |
Cryptochrome is a blue light receptor that acts as a sensor for the geomagnetic field and assists many animals in long-range navigation. The magnetoreceptor function arises from light-induced formation of a radical pair through electron transfer between a flavin cofactor (FAD) and a triad of tryptophan residues. Here, this electron transfer is investigated by quantum chemical and classical molecular dynamics calculations. The results reveal how sequential electron transfer, assisted by rearrangement of polar side groups in the cryptochrome interior, can yield a FAD-Trp radical pair state with the FAD and Trp partners separated beyond a critical distance. The large radical pair separation reached establishes cryptochrome's sensitivity to the geomagnetic field through weakening of distance-dependent exchange and dipole-dipole interactions. It is estimated that the key secondary electron transfer step can overcome in speed both recombination (electron back-transfer) and proton transfer involving the radical pair reached after primary electron transfer. |
|
| |
Address |
1] Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave, Urbana Illinois 61801, USA [2] Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, Illinois 61801, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Medium |
|
|
| |
Area |
WP5 In vitro |
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:24457842 |
Approved |
no |
|
| |
Call Number |
UNIBAS @ david.schuermann @ |
Serial  |
638 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lee, A.A.; Lau, J.C.S.; Hogben, H.J.; Biskup, T.; Kattnig, D.R.; Hore, P.J. |
|
| |
Title |
Alternative radical pairs for cryptochrome-based magnetoreception |
Type |
Journal Article |
| |
Year |
2014 |
Publication |
Journal of The Royal Society Interface |
Abbreviated Journal |
|
|
| |
Volume |
11 |
Issue |
95 |
Pages |
|
|
| |
Keywords |
|
|
| |
Abstract |
Alpha A. Lee†, Jason C. S. Lau, Hannah J. Hogben, Till Biskup‡, Daniel R. Kattnig and P. J. Hore⇑Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UKe-mail: peter.hore{at}chem.ox.ac.uk↵†Present address: Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK.↵‡ Present address: Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.Abstract
There is growing evidence that the remarkable ability of animals, in particular birds, to sense the direction of the Earth's magnetic field relies on magnetically sensitive photochemical reactions of the protein cryptochrome. It is generally assumed that the magnetic field acts on the radical pair [FAD•− TrpH•+] formed by the transfer of an electron from a group of three tryptophan residues to the photo-excited flavin adenine dinucleotide cofactor within the protein. Here, we examine the suitability of an [FAD•− Z•] radical pair as a compass magnetoreceptor, where Z• is a radical in which the electron spin has no hyperfine interactions with magnetic nuclei, such as hydrogen and nitrogen. Quantum spin dynamics simulations of the reactivity of [FAD•− Z•] show that it is two orders of magnitude more sensitive to the direction of the geomagnetic field than is [FAD•− TrpH•+] under the same conditions (50 µT magnetic field, 1 µs radical lifetime). The favourable magnetic properties of [FAD•− Z•] arise from the asymmetric distribution of hyperfine interactions among the two radicals and the near-optimal magnetic properties of the flavin radical. We close by discussing the identity of Z• and possible routes for its formation as part of a spin-correlated radical pair with an FAD radical in cryptochrome.
animal navigationflavinmagnetic compassradical pair mechanismspin dynamicsReceived November 15, 2013.Accepted March 3, 2014.© 2014 The Author(s) Published by the Royal Society. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
WP5 In vitro |
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
UNIBAS @ david.schuermann @ |
Serial |
637 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Marley, R.; Giachello, C.N.G.; Scrutton, N.S.; Baines, R.A.; Jones, A.R. |
|
| |
Title |
Cryptochrome-dependent magnetic field effect on seizure response in Drosophila larvae |
Type |
Journal Article |
| |
Year |
2014 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep |
|
| |
Volume |
4 |
Issue |
|
Pages |
5799 |
|
| |
Keywords |
|
|
| |
Abstract |
The mechanisms that facilitate animal magnetoreception have both fascinated and confounded scientists for decades, and its precise biophysical origin remains unclear. Among the proposed primary magnetic sensors is the flavoprotein, cryptochrome, which is thought to provide geomagnetic information via a quantum effect in a light-initiated radical pair reaction. Despite recent advances in the radical pair model of magnetoreception from theoretical, molecular and animal behaviour studies, very little is known of a possible signal transduction mechanism. We report a substantial effect of magnetic field exposure on seizure response in Drosophila larvae. The effect is dependent on cryptochrome, the presence and wavelength of light and is blocked by prior ingestion of typical antiepileptic drugs. These data are consistent with a magnetically-sensitive, photochemical radical pair reaction in cryptochrome that alters levels of neuronal excitation, and represent a vital step forward in our understanding of the signal transduction mechanism involved in animal magnetoreception. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Nature Publishing Group |
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Medium |
|
|
| |
Area |
WP5 In vitro; WP6 In vivo |
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
UNIBAS @ david.schuermann @ |
Serial |
636 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Fedele, G.; Edwards, M.D.; Bhutani, S.; Hares, J.M.; Murbach, M.; Green, E.W.; Dissel, S.; Hastings, M.H.; Rosato, E.; Kyriacou, C.P. |
|
| |
Title |
Genetic Analysis of Circadian Responses to Low Frequency Electromagnetic Fields in <italic>Drosophila melanogaster</italic> |
Type |
Journal Article |
| |
Year |
2014 |
Publication |
PLoS Genet |
Abbreviated Journal |
PLoS Genet |
|
| |
Volume |
10 |
Issue |
12 |
Pages |
e1004804EP - |
|
| |
Keywords |
|
|
| |
Abstract |
<title>Author Summary</title> <p>Low frequency electromagnetic fields (EMFs) are associated with electrical power lines and have been implicated in the development of childhood leukemias. However, the Earth also has a natural EMF that animals can detect and which they use in order to navigate and orient themselves, particularly during migrations. One way they might do this is by using specialised photoreceptors called cryptochromes, which when activated by light, generate changes within the molecule that are susceptible to EMFs. Cryptochromes are important components of animal circadian clocks, the 24 hour timers that determine daily behavioral and physiological cycles. We have studied the circadian behavior of the fruitfly and have observed some novel and robust effects of EMFs on the fly's sleep-wake cycle that are mediated by cryptochrome. By using cryptochrome mutants we find that our results do not support the classic model for how this molecule might respond to EMFs. We also show that mammalian cryptochromes can respond to EMF when placed into transgenic Drosophila, whereas in mammalian clock neurons, they cannot. Consequently, the EMF responsiveness of cryptochrome is determined by its intracellular environment, suggesting that other, unknown molecules that interact with cryptochrome are also very important.</p> |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Public Library of Science |
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
WP5 In vitro; WP6 In vivo |
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
UNIBAS @ david.schuermann @ |
Serial |
635 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hjalgrim, L.L.; Westergaard, T.; Rostgaard, K.; Schmiegelow, K.; Melbye, M.; Hjalgrim, H.; Engels, E.A. |
|
| |
Title |
Birth weight as a risk factor for childhood leukemia: a meta-analysis of 18 epidemiologic studies |
Type |
Journal Article |
| |
Year |
2003 |
Publication |
American Journal of Epidemiology |
Abbreviated Journal |
Am J Epidemiol |
|
| |
Volume |
158 |
Issue |
8 |
Pages |
724-735 |
|
| |
Keywords |
Adolescent; Adult; *Birth Weight; Child; Child, Preschool; Confidence Intervals; Humans; Infant; Infant, Newborn; Precursor Cell Lymphoblastic Leukemia-Lymphoma/*epidemiology/etiology; Registries; Risk Factors |
|
| |
Abstract |
Evidence has emerged that childhood leukemia is initiated in utero. High birth weight is one of the few birth-related factors that has been associated with childhood leukemia, albeit not consistently. The authors conducted a meta-analysis of studies of the association between birth weight and childhood leukemia risk. Study-specific odds ratios for leukemia were calculated, using a cutoff at 4,000 g of birth weight. The authors also evaluated whether the association between birth weight and leukemia followed a log-linear dose-response-like pattern. They calculated summary estimates using weighted averages of study-specific odds ratios from dichotomous and trend analyses. Eighteen studies (published between 1962 and 2002) were included, encompassing 10,282 children with leukemia. Children weighing 4,000 g or more at birth were at higher risk of acute lymphoblastic leukemia than children weighing less (odds ratio (OR) = 1.26, 95% confidence interval (CI): 1.17, 1.37). Furthermore, data were consistent with a dose-response-like effect (OR = 1.14/1,000-g birth weight increase, 95% CI: 1.08, 1.20). Studies of acute myeloid leukemia indicated a similar increase in risk for children weighing 4,000 g or more at birth (OR = 1.27, 95% CI: 0.73, 2.20) and a dose-response-like effect (OR = 1.29/1,000 g, 95% CI: 0.80, 2.06), but results varied across studies. Our findings support a relation between birth weight and childhood acute lymphoblastic leukemia risk and emphasize the need for additional studies of the biologic mechanisms underlying this association. |
|
| |
Address |
Department of Epidemiology Research, Danish Epidemiology Science Center, Statens Serum Institut, Copenhagen, Denmark. LIH@SSI.dk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0002-9262 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:14561661 |
Approved |
no |
|
| |
Call Number |
CBM.UAM @ ccobaleda @ |
Serial |
634 |
|
| Permanent link to this record |
